Is Tall Really Different from Giant?

 

I love learning new things, especially about Georgia’s native plants. It’s the beginning of goldenrod season and for years I’ve assumed (yes, assumed!) that all of the spreading roadside goldenrod near me is the species known as tall goldenrod (Solidago altissima) – now considered Southern late goldenrod (Solidago altissima var. pluricephala). Several things happened recently that made me take a look at a species I’d never considered: giant goldenrod (Solidago gigantea).

On a long roadside near my house - the same one with the elderberries that I wrote about in June - I noticed a tall, blooming goldenrod in the early part of August (which is early). I also noticed that the infloresence shape was different. These plants had a more openly branched inflorescence. When S. altissima blooms, its inflorescence has more of a pyramidal shape.

S. gigantea with smooth stems

The next thing that happened is that someone mentioned finding Solidago gigantea in a county near me, specifically saying that they identified it because of the smooth stem. So that started a thought in my head that maybe I was seeing something different.

Finally, while that thought was still percolating, I went to visit a friend’s garden and she had a large blooming goldenrod (again too early for normal tall goldenrod). We examined it and indeed the stem below the flowers was smooth. I stopped by the roadside near me on the way home to compare stems and – sure enough – they were smooth as well. I snagged a stem to take home for further inspection.

After further research (Weakley’s Flora, the awesome Astereae Lab at the University of Waterloo, and other references including range maps), I have decided that we do have Solidago gigantea nearby. It’s always exciting to find new species in my area!

Solidago gigantea, branched inflorescence

Solidago altissima, pyramidal inflorescence

How crazy are those names, by the way? Is tall (altissima) a word that really conveys a difference from giant (gigantea) in regards to these plants? Perhaps someone ran out of adjectives and could not think of another characteristic to use for the name? There are a few sites that also refer to Solidago gigantea as ‘smooth’ goldenrod. In my opinion, that is a better name.     

Gulf fritillary stopped by to visit the S. gigantea